This disclosure relates to a semiconductor module for a Switched-Mode Power Supply (SMPS) and to methods for assembling the module.
For some applications such as in the fields of telecommunication and computer electronics, it is desired to provide multi-device modules for switched-mode power supplies which include a control chip and one or more semiconductor power switches in a single package housing.
A feature of these modules is that the control chip and the power switch must be electrically isolated from each other. This can be achieved by the use of an additional electrical isolation layer positioned between the control chip and the die pad, as is known from U.S. Pat. No. 6,756,689 for example. The electrical isolation layer can be provided by a ceramic plate or by an adhesive tape. Alternatively, an isolation substrate can be provided under the power switch which electrically isolates the power switch from the die pad. However, this structure has the disadvantage that the chip design rules are limited.
These modules suffer from the disadvantage that the additional materials, in particular, the ceramic plate, increase the cost of the package. The isolation provided by an electrically insulating adhesive tape can also be unreliable. Additionally, the complexity of assembling the package is also increased which further increases the costs. These modules also suffer from the problem of delamination at the interfaces between the die pad and the isolation layer and between the isolation layer and the chip.